Traditionally, a train for passenger transport comprises a multiplicity of vehicles linked together. Each vehicle comprises a deck on which are installed a multiplicity of seats for the comfort of travelers. To increase the number of passengers able to be housed in a vehicle the concept is known, in existing technology, of a vehicle with two levels, vertically, comprising an upper and lower deck, each containing a multiplicity of seats. Such a double-decker vehicle is known by the person skilled in the art as a “duplex” vehicle.
A double-decker vehicle traditionally comprises an access door by which the passengers can enter the vehicle. The access door step is conventionally situated at an intermediate height between the lower and the upper decks of the double-decker vehicle. Staircases are provided between the step and the lower deck and between the step and the upper deck.
The presence of staircases is a major inconvenience for persons with reduced mobility because they constitute an obstacle to be passed (risk of falling, etc). By a person with reduced mobility we mean a person in a wheelchair or a person with a handicap (motor, visual, etc,) or a person with large or heavy pieces of luggage. Besides their worrisome nature for persons with reduced mobility, staircases have a limited life because of wear of the leading edge of the steps; this is also a disadvantage. Because of their steep angle, staircases require an excessive physical effort from passengers; this is a disadvantage. In addition, moving items of luggage in staircases is inconvenient.
An immediate solution to eliminate staircases would be to abandon double-decker vehicles and use only single-decker vehicles, but this solution is not economically viable. Another solution would be to add lifting platforms or elevators inside the vehicle. Even if we ignore the high cost of this solution, it greatly reduces the space available inside the vehicle, which is not desirable.